Couplings for sealingly joining the ends of two pipes are known in the art. Certain of these couplings, such as are disclosed by Magnani in U.S. Pat. No. 2,829,909, provide a sleeve fitted over the ends of the pipes, O-rings being provided between grooves in the inner surface of the sleeve and the external surface of the pipe to form a seal therebetween. The Magnani structure includes a plurality of longitudinally spaced O-rings engaging each of the pipes coupled by the sleeve. Straight-walled grooves fix the O-rings in the Magnani structure in a positive position, the Magnani structure being dependent for operation on the friction generated when the pipes are forced through the O-rings on assembly.
The present structure provides a seal coupling comprised of a sleeve mounted on the spaced ends of the coupled pipes, O-ring receiving pressure chambers being formed between the external surface of each pipe and the interior surface of a peripheral ridge formed in the sleeve. The O-ring receiving pressure chambers are essentially partitioned partially into two sub-chambers by an inwardly extending annular bead, the bead being located medially of the inner surface of each of the pressure chambers and extending toward but not into contact with the external surface of each pipe. The pressure chamber of the present seal allows the O-rings received within each chamber, one O-ring being disposed on each side of the annular bead, to travel when pressure thereon becomes a driving force. The present seal can therefore adjust to irregular or rough surfaces.
Accordingly, it is an object of the invention to provide a sleeve coupling for joining the spaced or contiguous ends of pipes, the sleeve having peripheral grooved ridges formed therein which define annular pressure chambers with the facing exterior surface of the concentrically enclosed pipe, the annular pressure chambers being partially partitioned by an inwardly extending annular bead formed on the inner surface of the sleeve, one O-ring being disposed on each side of the annular bead within each pressure chamber, the seal allowing travel of the O-rings on application of sufficient pressure to adjust the fit of the seal to irregular or rough surfaces.
These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.